The norepinephrine/catecholamine transporter (“norepinephrine transporter”) is essential for norepinephrine uptake at the synaptic terminals and adrenal chromaffin cells. In neuroendocrine tumors, the norepinephrine transporter is highly active and can be targeted for imaging and/or therapy with localized radiotherapy. One of the most widely used theranostic agents targeting the norepinephrine transporter is meta-iodobenzylguanidine (MIBG), a guanidine analog of norepinephrine. 123I/131I-MIBG theranostics have been applied in the clinical evaluation and management of neuroendocrine tumors, especially in neuroblastoma, paraganglioma, and pheochromocytoma. 123I-MIBG imaging has been used in the evaluation of neuroblastoma, and 131I-MIBG for the treatment of relapsed high-risk neuroblastoma, however, the outcome remains sub-optimal. Positron Emission Tomography (PET) tracers targeting the norepinephrine transporter and its targets represent a better option for the imaging and assessment after treatment of neuroblastoma, paraganglioma/pheochromocytoma, and carcinoids.
Integrins are a super-family of cell surface adhesion receptors, which control the attachment of cells with the solid extracellular environment, both to the extracellular matrix (ECM), and to other cells. Adhesion is of fundamental importance to a cell; it provides anchorage, cues for migration, and signals for growth and differentiation. Integrins are directly involved in numerous normal and pathological conditions, and as such are primary targets for therapeutic intervention. Integrins are integral transmembrane proteins, heterodimers, whose binding specificity depends on which of the 14 α-chains are combined with which of the 8 β-chains. The integrins are classified in four overlapping subfamilies, containing the β1, β2, β3 or αv chains. A cell may express several different integrins from each subfamily. In the last several decades, it has been shown that integrins are major receptors involved in cell adhesion, and so may be a suitable target for therapeutic intervention. Integrin αvβ3 regulates cell growth and survival, since ligation of this receptor can, under some circumstances, induce apoptosis in tumor cells. Disruption of cell adhesion with anti-αvβ3 antibodies, RGD peptides, peptide mimetic or non-peptide derivatives, and other integrin antagonists has been shown to slow tumor growth.
Thyrointegrin antagonists have been shown to effect tumor angiogenesis by interaction with integrin αvβ3. The effect of thyrointegrin antagonists is described in U.S. Pat. Pub. No. 2017/0348425 titled Non-Cleavable Polymer Conjugated with Alpa V Beta 3 Integrin Thyroid Antagonists, the contents of which are incorporated by reference.
A composition comprising both a thyrointegrin antagonist compound and a norepinephrine transporter target compound would be well received in the art.